When Evan MacIan, a fervent Catholic, becomes enraged by an atheist newspaper, he challenges the editor, James Turnbull, to a duel. Turnbull, just as passionate in his atheism as MacIan is in his Catholicism, eagerly accepts. Their sword fight interrupted wherever they go, MacIan and Turnbull duel with words. The more MacIan and Turnbull debate, the more they realize that they have more in common than they thought. They come to understand that their enemy is not each other, but a world that has grown too cold to tolerate men who not only believe in something, but believe in it enough to fight for it. MacIan and Turnbull gradually cease debating each other and begin to engage the people who interrupt their duel. Here we see G. K. Chesterton's great genius in his fiction: his ability to bring philosophical and theological ideas to life through his characters and stories. In The Ball and the Cross he accomplishes this with some of the wittiest and most engaging writing to be found in any of his novels.